Water based inks are well known for use on a wide variety of substrates. Such inks are generally latex emulsion or dispersion systems, water soluble resin systems or blends of the two systems. The water soluble resin systems are chiefly acrylics which are either thermosetting, thermoplastic or a blend of the two. Conventional water based inks include for instance latex systems as described in U.S. Pat. No. 3,533,811 the disclosure of which is incorporated herein by reference.
In the printing of designs on sheet vinyl covering materials, especially sheet vinyl flooring, it has previously been necessary to use hydrocarbon solvent based inks rather than water based inks to obtain satisfactory adhesion and quality. The solvents used with such solvent based inks frequently involve materials such as ketones and aromatic hydrocarbons which are considered hazardous and are subject to various anti-pollution rules and regulations. Water based inks have in the past been found to be unsatisfactory for use on vinyl plastics because of problems of adhesion and excessive mottle effect. These problems are especially severe in the printing of designs on sheet vinyl flooring where both good adhesion and a minimum of mottle effects are desired.